It's exactly as it sounds; Alzheimer's patients may soon be receiving visual and auditory stimulation as part of treatment for the impairments caused.  

Alzheimer’s is the 6th leading cause of death in the United States.
(alzheimers.net)

The research let by MIT found that applying strobe lights and low pitched buzzing sound produces brain waves typically lost in Alzheimer's.  In turn, the brain waves removed plaque, as well as improved cognitive functions in genetically engineered lab mice.

This isn't exactly a reason to be excited - yet.  The research is currently limited to the genetically engineered lab mice.  Brain waves are also known to work differently from humans to mice, so the results could be completely irrelevant.  Obviously, if it does work in human subjects, it would be a free method of cognitive improvement (read: anti-dementia).

Worldwide, nearly 44 million people have Alzheimer’s or a related dementia. (Alzheimer’s Disease International)

What is going on?

This is stacking upon previous work done which showed that flashing a light at a rate of 40/s with the engineered mice would treat their engineered Alzheimer's. Upon the addition of sound at a similar frequency, the results were improved more.

Ultrasound bursts were also used in previous studies that allowed injected microscopic bubbles to expand and contract rapidly, in turn forcing the walls of surrounding blood vessels to 'leak'.  During this time, there is a temporary gap in the blood-brain barrier, which allows antibodies to cross to the brain.  Those antibodies get microglia cells to then destroy the amyloid proteins causing the impairment in the brain.

Alzheimer’s and other dementias are the top cause for disabilities in later life. (Alzheimer’s Disease International)

Cause for hope?

Well, it does look better than it ever has.  There have been a series of studies, all getting closer to a distinct cure.  There is tons of funding, and tons more still needed.  The research is starting to pick up pace, especially with society starting to see the viable use for stem cells, among other technologies we have at our disposal.  

Alzheimer's Disease can end this generation, and it appears we are fast on track to meeting that goal.